dify - 💡(How to fix) Fix Langfuse trace is not emitted after advanced-chat workflow resumes from human-input node

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Dify version

1.14.1

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

1. Deploy Dify self-hosted 1.14.1.

2. Configure Langfuse tracing for an advanced-chat app.

3. Verify Langfuse tracing works for a normal WebApp run that does not pause.

4. Add a human-input node to the advanced-chat workflow.

5. Publish the app and open it from the WebApp.

6. Send a message that makes the workflow reach the human-input node.

7. Confirm that the workflow becomes paused.

8. Submit the human-input form from the WebApp.

9. Confirm in Dify that the same workflow run eventually succeeds.

10. Search the final workflow_run_id in Langfuse traces.

Example evidence from my environment:

• The workflow run exists in Dify and succeeds.
• The run has a submitted human input form.
• The same workflow_run_id cannot be found in Langfuse.

✔️ Expected Behavior

After a paused advanced-chat workflow is resumed from a WebApp human-input form and finishes successfully, Dify should emit a Langfuse trace for the final workflow_run_id.

The resumed workflow should behave the same as a normal non-paused WebApp run from a tracing perspective.

❌ Actual Behavior

The workflow run succeeds in Dify, but no Langfuse trace is emitted for the final workflow_run_id.

Normal non-paused WebApp runs from the same Dify app can be traced successfully, so this does not appear to be a Langfuse connectivity or credential issue.

The issue only appears on the human-input pause/resume path.

Additional debugging showed that the paused workflow resumption context restores AdvancedChatAppGenerateEntity with trace_manager=None.

The trace_manager field is defined with exclude=True:

trace_manager: "TraceQueueManager | None" = Field(default=None, exclude=True, repr=False)